Abstract: The present invention relates to a method for treating an aqueous liquid effluent containing calcium and carbonate ions and containing precipitation-inhibiting products, said process comprising the following successive steps: a) providing an aqueous liquid effluent supersaturated with CaCO3 and containing precipitation-inhibiting products; b) having the effluent obtained in step a) pass into a reactor with high solid content with a solid content maintained between 20 and 800 g/l and integrated solid-liquid separation, at a pH comprised between 8 and 9.2 allowing in a single step precipitation in situ of the aragonite polymorph of calcium carbonate and removal of the precipitation-inhibiting products; c) recovering an aqueous liquid supernatant containing a suspended solids content of less than or equal to 0.1% by mass of the solid content in the reactor, advantageously a suspended solids content of less than 50 mg/l, the precipitation-inhibiting products being phosphonates.

Abstract: The present invention relates to a method for treating an aqueous liquid effluent containing calcium and carbonate ions and containing precipitation-inhibiting products, said process comprising the following successive steps: a) providing an aqueous liquid effluent supersaturated with CaCO3 and containing precipitation-inhibiting products; b) having the effluent obtained in step a) pass into a reactor with high solid content with a solid content maintained between 20 and 800 g/l and integrated solid-liquid separation, at a pH comprised between 8 and 9.2 allowing in a single step precipitation in situ of the aragonite polymorph of calcium carbonate and removal of the precipitation-inhibiting products; c) recovering an aqueous liquid supernatant containing a suspended solids content of less than or equal to 0.1% by mass of the solid content in the reactor, advantageously a suspended solids content of less than 50 mg/l, the precipitation-inhibiting products being phosphonates.